Don't let fear of cold weather cloud your vision of the perfect winter vacation. Low-season trips to spots where winter weather reigns are where it's at, for many reasons. An off-peak destination affords budget travelers the rare chance to splurge: Luxury accommodations and flight upgrades become within reach during winter at popular destinations around the world. Plus, crowds are sparse and deals are plentiful. Here are five awesome and affordable spots to consider visiting this winter.

Blue Lagoon (Photo: Icelandair)

Iceland

For those of us in the northern hemisphere, it may seem counterintuitive to head north for the winter. However, Iceland offers thermal refuge during the coldest months of the year thanks to its many geothermally heated springs and pools. A hike through the Icelandic countryside often yields the chance to submerge in steamy hot springs. And the celebrated bath-like Blue Lagoon is, arguably, best visited on a brisk winter day, when the toasty mineral waters and blood-warming cocktails offer a welcome thaw.

Airfares to Iceland during winter are notably lower than those in summer. Icelandair, which flies from eight U.S. cities to the Nordic country and beyond, is a great choice for low-priced winter airfare. We spotted flights from New York to Reykjavik for as low as $622 round-trip in early February, via a Hacker Fare on Kayak (combining flights on Icelandair and Norwegian Air). The lowest fares we found for June and July travel started at $837 round-trip.

Iceland is also the perfect place for a winter stopover if you're heading to Europe. Check out Icelandair's free stopover package and take advantage of those affordable low-season airfares.

Hotel Monaco, Philadelphia (Photo: TripAdvisor, LLC)

Philadelphia

Philadelphia is an ideal winter destination because so many of its top historical attractions are indoors. It doesn't really matter how cold it is outside when you're taking in a Matisse at the Barnes, exploring Independence Hall, or fiddling with hands-on exhibits at the newly renovated Benjamin Franklin Museum. Plus, there'll be far fewer crowds to contend with while you're learning about Mr. Franklin's affinity for musical inventions and printmaking.

Not all Philadelphia properties offer clearly discounted seasonal rates. Still, it's common to see comparatively lower prices at many hotels during winter, and it didn't take us long to unearth a few examples: At the Hotel Monaco Philadelphia, we found rates in late December for as low as $135 per night, compared to June, when the lowest nightly rates amount to $189. At Rittenhouse 1715, nightly room rates start at $219 during January; in spring, those prices bump up to $239.

Bucharest made our list of 10 Places to Go While They're Still Cheap this year. It's almost always inexpensive to visit Bucharest, compared to other major European cities. Better yet, it's an even more affordable place to visit during winter. From airfares to hotel rates, prices drop sharply with the temperature. This winter, you can get from JFK to Bucharest on Turkish Airlines for as little as $724 round-trip, with a stop in Istanbul. (Try a free stopover and get two cities for the flight price of one.)

Hotels are cheaper too, naturally. At Hotel Christina, the number-one rated Bucharest hotel according to TripAdvisor (our parent company), prices are the lowest all year during winter months. In February, for example, nightly rates come to €50 (about $63). In June, though, rates jump to €70 (about $87) per night. At Hotel Epoque, the best available rate in June came to €170 (about $212). In January, you can grab a room at this historical and luxurious property for as little as €128 (about $159) per night.

(Photo: Banff Lake Louise Tourism/{aul Zizka Photography)

Banff National Park

Banff National Park is achingly beautiful in wintertime. Whether seen from the ground by sleigh, snowshoe, or dogsled or viewed from the comfort of a fire-warmed room, the park's snow-dusted mountains and turquoise lake appear dreamlike against a pale winter sky.

Banff is full of well-known luxury properties that can cost an arm and a leg come spring and summer—but we found rates dropping by almost half during winter. For example, let's look at the local Fairmont resorts: If you want to stay at Banff's iconic and luxurious Fairmont Banff Spring, go soon. During winter, rates fall as low as $359 CAD (about $317) per night. Comparatively, the best available rate in July is $609 CAD (about $539). Same goes for the Fairmont Chateau Lake Louise. Grab January rates starting at $299 CAD (about $265). In June? Those prices skyrocket to $559 CAD (about $495) nightly. Moreover, both properties are offering a range of deals during winter, from free nights to complimentary resort credits with your stay.

It's rare to see a U.S. ski destination offering lower seasonal rates during winter. There's an exception, though: Denver, Colorado. Though it isn't exactly a ski spot itself, the Mile-High City makes an ideal base for winter sports. It's close to Winter Park Resort and Loveland Ski Area. Plus, Rocky Mountain National Park, about an hour away, offers non-downhill activities, from hiking to snowshoeing to cross-country skiing in pristine park wilderness. Rent a car, take a few day trips, and return to Denver after the sun sets to enjoy the city's fabulous nightlife and restaurants. The best part? You'll save money on accommodations, and you can fly right into Denver International.

There's a general uptick in Denver room rates when the weather gets warmer. At the Four Seasons Denver, for example, weekday winter rates start at $525 per night in January. Comparatively, weekday nights in June cost $100 more. Denver's Magnolia Hotel offers weekday January rates from $215 per night. In June, those rates rise to $242.